Process for the insertion of the weft in a loom



United States Patent [111 3,543,807

[72] Inventor Albert E. Mocuinger [56] References Cited Epalingesswi'wland UNITED STATES PATENTS I g figg'g 2,630,839 3/1953 Birtweil139/125 9 Continuation-impart of Ser. No. 501,651, FOREIGN PATENTS Oct.22, 1965, abandoned. 648,576 8/1937 Germany 139/125 [45] Patented Dec.1,1970 332,102 10/1958 Switzerland 139/134 Primary Examiner-Henry S.Jnudon [s4] PROCESS FOR THE INSERTION OF THE WEFT and shalbway IN A LOOM15 Claims, 14 Drawing Figs.

[52] [1.8. CI. 139/125 ABSTRACT: The invention provides a method ofweaving and [51] In. D03d an apparatus for weaving wherein a grippershuttle is [50] Field of Search 139/12, 13, presented at a shed entranceat the same point of time each weaving cycle.

Patented Dec. 1,1970 v 3,543,807

Sheet 1 of 5 I8 ea INVENTOR ALBERTEMCSESSINGER Patented Dec. 1,1970$543,807

Sheet 3 of5 FIG. 9

, I INVENTOR ALBERTEMOESSlNGER 2 Q a 5 ATTORN Y Patentd Dec. 1, 19703,543,807

Sheet 4 015 F FIG. 19

d TIME i F '1 l 1 52' 2G 8 A esn DISPLACEMENT FIGH 52 78 INVENTORALBERTEMESSINGER ATTORNEY Patent ed Dec. 1, 1970 3,543,807

Sheet 5 of 5 \V INVENTOR 200 200: 2002 2003 F36 I 4 ALBERTE.MOESSINGERFIG. l3 BY jw pwgm PROCESS FOR THE INSERTION OF THE WEFT IN A Thisapplication is a continuation-in-part of application Ser. No. 501,651filed Oct. 22, 1965 now abandoned.

"The present invention relates to a process and apparatus for theinsertion of a weft yarn in a loom, wherein the shuttle travels withoutstopping in a closed circuit, picks up the weft yarn offered at theentrance of the shed, and releases it at the exit of the shed, continuesits course and comes back to catch a new end of yarn at the entrance ofthe shed.

The difficulties of such a process lie in the impossibility ofcontrolling the braking or slowing of the shuttle during its free motionin the shed. The braking causes said shuttle to arrive at the exit ofthe shed at a variable time and speed.

This slowing of the shuttle during each passage in the shed may cumulatein such a manner that its movement will soon be dephased with respect tothe cycle of the loom, so that the loom must be stopped and started inrenewed phase.

To overcome this disadvantage, the machines used to date stop theshuttle at the shed exit: push the shuttle into a return channel whichdirects it toward its launching position, and launch it into the shed ata well determined moment in synchronization with the cycle of the loom,while it pulls a weft yarn offered at the entrance. The completestopping of the shuttle during its cycle causes a loss of time whichlessens the time reserved for the passage of the shuttle in the shed. Inaddition, it requires complicated and precise mechanisms, which aresubjected to great stress during the acceleration of the shuttle, andwhich are subjected to unavoidable wear and tear due to the braking ofthe shuttle. I

To avoid the stopping of the shuttle, some manufacturers proposed todrive the shuttle in the return channel at a constant speed and toseparate the mechanism of the loom Beater", shed, etc...) from themechanism used for the movement of the shuttle by using magneticcoupling and brake actuated by the passage of the shuttle upon its exitfrom the shed. This construction requires an adjustment at each cycle ofthe loom, which adjustment is difficult due to the inertia of thebeater, shed, etc., driving mechanism mass, and therefore requires greatefforts to delicately adjust the movement of a great mass.

Other builders have proposed that the shuttle be controlled at avariable speed. There the shuttle driving means are connected to themain shaft of the loom by a speed variator actuated by the passage ofthe shuttle at its exit from the shed. Since the variation of the speedis effected progressively, it will be also effective on the followingshuttle which may not need it.

To reduce the dephasing of the shuttle during its passage through theshed, it has also been proposed to drive. it by means of a magneticfield acting in the shed and at the speed changes of the shuttle. Theforces exerted by the magnetic field upon the shuttle will be a,function of the differences of speed of the shuttle and magnetic field.A delayed shuttle may be acceleratei up to its normal speed (i.e., thespeed of movement of the magnetic field), but will not be able to catchup the delay in question. Thus, these looms have to resort to theconventional means of stopping the shuttle on the return trip to move ittoward the launching point in the shed, in. synchronization with theloom.

This invention consists mainly in a electromagnetic system which actsupon the shuttle during its passage into the return channel and controlsthe movement of said shuttle in such a hand, the magnetic field actingon the return path of the shuttle as in this invention may surround theshuttle on all sides and therefore annul any action other than axiallyacting forces. I

To provide weaving apparatus and loom wherein a gripper shuttle arrivesat the shed entrance at the same point of time in each weaving cycle.

Means for compensating for friction and other factors which tend to slowa gripper shuttle and cause it toarrive at the shed entrance at varyingpoints of time.

To prevent cumulative slowing of a grippershuttle in its passage througha series of weaving cycles to a point where the machine must be stoppedand the cycle started with the shuttle rephased.

To provide electromagnetic means for varying gripper shuttle speed inaccordance with the deceleration of said shuttle during its passagethrough a shed. To provide combined physical and electromagnetic drivemeans for a shuttle which serve to present the shuttle at the shedentrance at the same point of time in each weaving cycle.

The invention may best be understood by reference to the drawingswherein like numerals represent like elements and wherein:

FIG. 1 represents a sectional view taken along line AA of FIG. 2;

manner that it reaches its launching point in the shed 'at a FIG. 2represents a sectional view showing a loom embodying the presentinvention;

FIG. 3 represents a gripper shuttle picking up a thread at its entranceto the shed;

FIG. 4 is a top view of the shuttle of FIG. 3;

FIG. 5 represents the gripper shuttle releasing a thread at it exit fromthe shed;

FIG. 6 represents a top view of the shuttle of FIG. 5;

FIG. 7 illustrates a driving wheel of the present invention located atthe exit to a shed;

FIG. 8 represents a top view of the wheel of FIG. 7;

FIG. 9 represents the structure of the drive wheel carrying a shuttle ina channel;

FIG. 10 illustrates the synchronization diagram of shuttle movement;

FIG. 11 illustrates control means for the electromagnetic means;

FIG. 12 illustrates another synchronization diagram of shuttle movement;

FIG. 13 illustrates control means for the electromagnetic means; and

FIG. 14 illustrates control means for the electromagnetic I means;

FIGS. 1 and 2 show the general arrangement of the loom, illustrating theprincipal mechanisms necessary for the formation of the fabric, FIGS. 3,4-, 5 and 6 show-the pick up of the yarn in the insertion box and thefreeing of the yarn in the shuttle reception. box, and FIGS. 7, 8 and 9show the detail of a magnetic disk actuating the shuttle, FIGS. 10 and12 are a time-path diagram showing two examples of synchronizationof theshuttle, and FIGS. l1, l3 and 14 show the electrical connectionscreating the magnetic flow which. effects these synchronizations. t

In FIG. 1, the warp beam 27 turns around its axle in the bearingsaffixed on frame 85. Said warp beam unwinds the 'warp yarns 11 and 13 asthe fabric advances by means of known mechanisms which are not shown.The warp yarns and 13 pass on cylinder 29, are separated by divisions31, and pass in the heddles of frames I9 which spread them apart to formthe shed l4. Said shed l4 closes again upon the formaon the fabric beam35 rotating in bearings affixed on frame 85.

Frame 85 also has bearings in which rotates the main shaft 67 on whichare keyed the double earns 43 which impart motion to the lay. Conicalgears 42 and a braking pulley 71-are keyed on this same shaft. Next-tobraking pulley 71, driving pulley 69. is mounted on shaft 67 on which itcan turn freely. Lever 103,

rotating around its fixed axle 104, exerts a pressure between thedriving pulley 69 and the braking pulley 71, in such a manner that themachine is driven by a motor and belt (not shown). To start the machine,lever 105 is turned in a counterclockwise direction, which tightens thecoupling by means of rod 106 .and releases the (brake) strap 107 of thebrake pulley 71 through rod 108, 10 stop the machine, lever 105 isturned in a clockwise direction," which releases coupling 69 and brakespulley 71. The coupling pulley is provided with a great mass, in such amanner that it acts as a flywheel or steadying force when the loom is.in operation.

Double earns 43 act through the intermediary of rollers on the doublelevers'41 which actuate levers 3'!- lay 110 in which is affixed comb 17.

Main shaft 67 also carries affixed thereto a gear 111 which imparts toshaft 89a rotating motion. with a number of turns equal to a simplefraction of the number of turns of the main shaft, through theintermediary of gears 112 and 1 13. In the example illustrated, shaftturns half as fast as shaft 67.. On this shaft 89 age affixed earns 21which act through the intermediary of rollers 114 on bent levers'orbellcranks 23, raising and lowering at the desired rhythm rods 25 andframes 19 which are brought back by springs 101.

The conical gears 42engage with conical gears 40 affixed on shafts34which are perpendicular-to the main shaft 67. The

twoshafts 34 and shaft 67 are located in the same plane. The

carrying the shuttle revolving drums 20 and 22 are affixed at theextremities of said shafts 34.

The circuit in which shuttles' 52 travel is formed by, the receivingchannel :56 which receives the shuttle'52 when it comes out of the shed,the semicircular channel 26 in which the shuttle is taken by'therevolving drum 22, the rectilinear return channel 18 in which theshuttle is accelerated or braked, as explained later, by a magnetic flowcreated for this purpose, depending upon whether it is late or early,the semicircular channel'24 in which the shuttle, synchronized inchannel 18, is pulled by means of a spigot or catch 74 affixed on therevolving drum 20, and finally the rectilinear channel 120 which guidesthe shuttle in the direction of shed 14 which forms the last portion ofsaid circuit. The three portions 120, 14 and 56 aredirected in the samedirection and are tangent to the semicircular channels 24 and 26;similarly, channel 18 is tangent to the other extremity of thesesemicircular channels.

As we can see in the example of FIG. 2, while a shuttle 52 is launchedinto the shed by the drum 20, a secondshuttle has been launched.by-drurn 22 into return channel 18. Upon passing in front of opening115, a fixed cam 116 opens the clip 117 of the first-mentioned shuttle52, which hooks the warp yarn 118 (FIGS. 3 and 4). When the shuttle cliparrives at the on stop 123, cam 116 closes clip 117 which holds the yarnheight of the fabric; yarn118 has slid to the bottom of the clip,

while fixed clip 38 opens to free the extremity of the yarn 1'18.-

and 6). To prevent said extremity from jumping back into the.

shed under the influence of it's elasticity, clip 117 of the shuttle isopen in such a manner that the yarn extremity coming out of the shed isbig enough and is offered to a slit 121 which sucks in saidyarn by meansof air suction. To limit to the minimum.

the losses of yarn, the warp yarn is then pulled out in a directionopposite that of its insertion by a specific amount.

This insertion process is the objectof copending US. Pat. applicationSer. No. 501,652 nowU.S. Pat. No. 3,378,040.

FIGS. 7 and 8 show an example of drum22 in a front and sectional view.Drum 22 is formed of ,two discs 28 and 30 made of ferromagnetic materialconnected at their center bya hub 46 also made of ferromagnetic materialand affixed on a, shaft 34 rotatingin a fixed portion in which areaffixed ball bearings 36A and 36B. Said shaft is rotated, by mea'ns of aset of conical gears, gear 40 being affixed on shaft 34 and gear 42being affixed on main shaft 67. Around said hub 46 is mounted a solenoid44 inwhich passes an electric current 1 creating a magnetic flux whichwill be guided in said hub 46 and will spread into discs 28 and 30. if ashuttle 52 comes near, the periphery of these discs, as indicated inFIG. 9, it will close the circuit of the magnetic flux and the shuttlewill be strongly attracted against these two discs. The intensity of themagnetic flux will be calculated in such a manner that the attraction ofthe shuttle against the discs will be greater than the centrifugalbetween the two discs 28 and 30 to the fixed portion 56 of the machine.The fixed portion 48 will preferably be made of nonmagnetic andelectrically insulating material to prevent any loss of energy.

Upon passage of the shuttle from the semicircular channel I to therectilinearchannel 18, the removal of the shuttle from" said discs 28and 30 is facilitated by disc 60 located between said discs 28 and 30and which projects slightly over their periphery. The arrangement mustbe such that the tangential line passing through the periphery of discs28, 30 and 60 have the same direction as channel 18. Disc 60 is affixedon fixed axle 62 through the intermediary of ball bearing 64, said axlebeing integral with an extension 58 of the fixed portion 48.

Disc 60 is preferably made of an electrically conductive material whichis nonmagnetic, for example, aluminum; it mayturn'freely between theopposite sign magnetic poles of the discs 28 and 30. Under the action ofthe magnetic field in mo 'tion with discs 28 and 30, a parasiticelectric current is created in the aluminum disc 60 which rotates it ata speed substantially equal to the peripheral speed of discs 28 and30.When the shuttle will pass the tangential point'66 of the rectilinearchannel 18 and of the semicirc ular channel 26,'it will be lifted -bydisc 60, which immediately decreases the magnetic attraction force.

Shuttle 52 will be launched at the peripheral speed of drum 22 intochannel 18, along which is placed a whole series of solenoids 68creating a magnetic field in said channel. The

solenoids will be fed according to a well determined plan, as will beexplained later, in such a manner that the shuttles always arrive at thesame moment of the loom cycle at the outlet of said channel-18,regardless of the moment of entrance. .The

variable delay incurred by the shuttle during its free passage throughthe shed thus will be compensated for, and the shuttle will remainsynchronized with the cycle of the loom. Since the shuttle issynchronized when it comes out of channel 18, it will enterinto thesemicircular channel slightly prior to the driver 74 of drum 20, whichis driven by the loom and is therefore synchronized.

To absorb any-speed difference between shuttle 52 and v drum '20 andprevent the shuttle from hitting driver 74, an electromagnet 76 ismounted on said drum, creating a pressure between disc and shuttle. Thispressure-may be selected as greater than thecentrifugal force exertedupon the shuttle to eliminate any rubbing in the semicircular channel.The excitation of the electromagnet may beinterrupted by.conventionalmeans to allow the shuttle to leave, along the tangent in channel 120,for example, bya switch (not shown) attached to the channel 24 andadapted to be brushed by means 76. Thus, the shuttle will belaunchedinto the shed 14 at a time and speed determined by the spigot 74 of drum20, therefore absolutely in synchronization with the loom cycle.

To synchronize a shuttle which has been delayed or dephased during itsfree movement through the shed, sole- I noids 68 will be fed temporarilyaccording to a predetermined law, which is'indicated as an example inFIG. 10, which illustrates a timegpath diagram. The X-axes (abscissae)show the lengths; the distance comprised between 0 and 1 represents thelength of channel 18'along which the position of the solenoids 68 hasbeen indicated. The Y-axis (ordinate) indicates the times; the value t'represents the time at which a synchronized shuttle arrives at theextremity of channel 18, i.e., arrives on drum 20. The point F istherefore defined by the time rand the length l of channel'18.

The shuttle arrives in channel 18 (on the Y-axis 0) between the times Aand D, which-represent the extreme limits 'of dephasing of the shuttle.If the shuttle'arrives in channel 18 with a greater dephasing, thiscannot be corrected and the machine will have to be stopped. For thesmoothest possible operation of the loom, it is necessary to beable tocorrect shuttle dephasings' as large as possible, i.e., the distancebetween A and D must be as long as possible. v

The height of the shaded surface upon the emplacement of each solenoid681, 682', etc., represents the time during which each solenoid 68 isexcited. The curve aandd represents the extreme movements betweenwhichthe shuttle may move. At time t, shuttle 52, located at 52, i.e.,in, one of the most dephasing positions, will be subjected to anattraction inside the magnetic field attracting it between the twocurves a and d, therefore slowing it down. Similarly, a shuttle locatedat 52", will be subjected to an attraction attracting it between the twocurves a and d, therefore accelerating it. On the other hand, a shuttlelocated at- 52" in a substantially homogeneous magnetic fieldwill not besubjected to anychange in speed, since the magnetic action is-beingexerted inboth directions. I 7

When the distance between the two curves 0. and d is too big, it mayhappenthat a shuttle arrives in the movement correction zone (curvea ord) with a speed that is too different from that that it should takeafter correction, in such a manner that the magnetic forces acting thenare not sufficient: A shuttle which follows curve a at the beginning maybe braked by some outside cause (friction) in the return channel; itstrajectory will curve in progressively (dotted line e) and will reachcurve d where it will then feel the effect of the magnetic forces; atthat time, it is possible that the speed of the shuttle may have beenreduced so much that the magnetic forces exerted along curve d would notbe sufficient to accelerate it and force it to stay inside curves 0 andd.

To avoid this disadvantage, a succession of connecting diagrams ofsolenoids 681- 6811 is provided, for the purpose of subdividing thefield comprised between the curves a and d of FIG. 10 into a successionof fields comprised between the curves a and b, band 0, c and d. Onlyone of these fields will operate at any one time; it will be selected incorrespondence with the time of entrance of the shuttle into channel 18.An example of electric diagram which permits the installation describedabove is given in FIG. 11. a

As described in FIG. 1, the shuttle 52' coming out of shed 14 is pickedup by the receiving channel 56 and the moment of its passage isdetermined by a conventional proximity detector 78. Shuttle 52, whenpassing in front of said detector 78, induces an impulse transmitted tothe rotative selector 80 which rotates at the rhythm of the loom, i.e.,one turn per filling through one of the rotativeselectors 84, 85, 86which is coupled thereto. At the moment of the triggering of thethyratron, the rotative selectors are in contact with a'wide' key orcontact 130, 140 and 150 throughwhich passes the current of thecorresponding thyratron through a resistance 160, which serves to limitthe current to the minimum necessary to keep the thyratron in charge. Atthat moment, nothing yet'will happen in the solenoids 68 of channel 18;with the loom and "the shuttle continuing their movement, the rotativeselectors will continue to rotate until they come in contact with keysor contacts noid68-1. will be exactly the time necessary for shuttle 52to; pass from detector 78 to the first solenoid 681 ofchannel 18, i

it will be given by the angle comprised between the keys 8 1 and 1301,which is the same as between the keys 82 and 1401 and as between 83 and1501, as can be seen in FIG. 11. Upon rotating, one of the rotativeselectors 84 or 85 or 86 will feed successively the solenoid 1301. 13011or 1401 14011 or 1501 15011. The keys or contacts 13011, 14011 and 15011will feed the last solenoid approximately atthe same time, since theshuttle is to arrive at the extremity of the channel at the same moment.Thus the solenoids will be fed successively as the rotative selectoradvances. To obtain an excitation of the solenoid 68 in the timeaccording to the diagram of FIG. 10; in which several solenoids areexcited at the same time, each one having differentignition andextinction times, the keys or contacts shall be placed in a cylinder,these keys being staggered or shifted axially so as to be able to givean independent contact at the same time as another key. This can beillustrated easily with three diagrams according to FIG. 10 whereincylindrical surfaces are spread out flat, the lengths being in thedirection of the axis of said cylinder, the times being curved.

Each of the cylinders of rotative selectors 84,85 and 86 will receiveone of these diagrams, after metallization of the following shadedsurfaces: For selector 84 the shaded surfaces comprised between. curvesa and b, i.e., field ABF; for selector 7 It is clear that to increasethe regularity of the travel of the shuttle in the return channel, it ispossible. to increase the number of solenoids. It is also possible toplace current amplifiers between the rotary selectors 84, 85 and 86 andthe solenoids 86; it would also be possible to subdivide the time ofaction into more than three zones, as shown in the example given. I

If the shuttle arrives at 78 after selector 89 has passed over contact83, the shuttle will arrive too late to be taken in a magnetic fieldcontrolled by selectors 84, 85 or 86; an additional contact 84A istherefore provided, which will send an impulse in the thyratron 160which passes the current of the source yarn. A determined amount of timewill occur between the thyratrons (amplifiers) 79 according to themoment 'of' passage of the shuttle, i.e., according to contact 81, 82 or83 in front of which is the rotative selector at that time. This impulsetriggers said thyratron which then releases the current through asolenoid 161, whichwill trigger the click or catch 162, thus freeinglever which, under the action of spring .163, will block the handbrake107 through the intermediary of rod 108. Solenoid 161 will, through thesame movement triggering click 162, trigger the supply current of themotor M which drives the loom.

Another example of electromagnetic control synchroniza tion of theshuttle during its return tripisshown in FIGS. 12 and 13. Solenoids 200are placed much closer together than in the preceding example, and theymay even touch each other.

Their division will have a very determined value which, with thefrequency of an alternating current, will produce a magnetic fieldmoving in the direction of the axis ofchannel 18 at a determined speed.This system will act as an electric motor which would have been openedand'developed following a straight line. For a determined distributionof the solenoids,

the speed of displacement of the flux may be changed by changing thefrequency of the supply current.

To be able to synchronize a shuttle which has been dephased during itspassage in the shed, it will have to be, according to FIG. 12, taken inchannel 18 toward point P, whatever the moment at which the shuttleenters said channel. It may, for example, have a constant speed betweenA and F or Dand F, which will imply a different feeding frequency in thecase where the shuttle arrives at A or at D. (The speed is illustratedin a time-path diagram by the slope of the curve which represents themovement). x

The diagram of FIG. 13 indicates, as anexample, a means to adapt thefrequency of the supply current of solenoids 200 in function of the timeof passage of the shuttle. A cam 201 is actuated by the main shaft 67and rotates in a clockwise direction (arrow 202). The little wheel orfollower 203 is applied-on said cam 201 by means of spring 204. When cam201 is in the position illustrated in the drawing, little wheel 203comes down'the curve and the ferrous mass 205 penetrates in choke coil206, changing its impedance and consequently the frequency of theosciilatingcircuit formed by choke coil 206 and condenser 207.,The formof cam 201 will be determined in such a manner that each position of thecam corresponds, in the oscillating circuit, to the frequency giving tothe magnetic flux of solenoids 200 the speed determined in the diagramof FIG. 12. When the shuttle passes over detector 78, it produces in thelatter a pulse which results in the triggering of the thyratron 222permitting the feeding of solenoid 209. The hub 210 of said solenoid 209will then be attracted by the magnetic flux and will hold part 212between a brake 220 and] a fixed portion 213. The-ferrous mass 205 willthen be fixed in the position that it has at the moment of thetriggering produced by detector 78, and the little wheel will stay inits position without following the. cam. The frequency of theoscillating system 206207 will therefore remain constant and will keepthe desired value until solenoid 209 is triggered by the loom by meansof contact 221 through the intermediary of a cam (not shown). Contact221 can be closed immediately, the current being then disconnected bythe thyraton 222. Little wheel 204 will fall back upon cam 2011 and thecycle will be repeated upon passage of the next shuttle. Through thismeans, the shuttle may arrive at any moment between the limit values Aand D, the speed of the magnetic flux will be comprised between VA andVD and will be directed toward point F of the diagram of FIG. 12.

Since the shuttle arrives in channel 18 always with the same speed VRwhich is the speed of drum 22, it is possible that the differencebetween the shuttle entering speed and the speed of the correspondingmagnetic flux, VD forexample, be too great to be driven without too muchsliding. It is then possible to divide the unit formedby solenoids 200of channel 18 and the linear inotor, into three sectors 1, ll and illwhich will each be fed by a determined frequency corresponding to thefrequencies necessary to obtain the speeds indicated in full lines onthe diagram of FIG. 12. The control of these frequencies will beeffected as in the preceding example and is shown in FIG. 14.

On rod 230 actuated by follower 231 contacting cam 202A on shaft 67A andspring 232, three ferrous masses 2051, 2052 and 2053 each influence itsown oscillating system 01, 02 and 03 controlling the three groups ofsolenoids 2001, 2002 and 2003. The form of these ferrous masses will beselected in such amanner that for the same displacement, the variationsof the choke coil correspond to the frequency variations prescribed bythe diagram of FIG. 12. As in the preceding ex- Of course, the inventionis not to be interpreted as limited to herein described specificembodiments but may include. I

equivalent means and obvious modifications. I,

I claim:

I. A method of weaving comprising the steps of moving a Q grippershuttle without a stop in a closed circuit, said circuit includingpassage through ashed having an entrance and an exit, causing saidshuttle to pick up a weft yarn at the shed entrance with a constantspeed, causing said shuttle to release the yarn adjacent the shed exit,and continuously repeating the steps of picking up and releasing theyarn while controlling the shuttle motion by a successive and programedenergization of a plurality of electromagnetic means in spaced relationwithin the return channel so that the shuttle always reaches in onedirection into the shed wherein they traverse same under the influenceof inertia, the improvement comprising: a

detection means indicating the variable delay of each shuttle atthe'exit of the shed, first electromagnetic means adjacent to therectilinear return channel and exercising directly a magnetic force andlimited to the shuttle that has been detected previously, without anyaction of the projecting means and control means for said firstelectromagnetic means.

3. The apparatus of claim 2 wherein the means to project said grippershuttles comprises a drive wheel adjacent one semicircular channel, saiddrive wheel having magnetic means to hold a shuttle against thewheelwhile said shuttle is in said semicircular channel.

ample, amplifiers A1, A2 and A3 are provided between the oscillatingcircuit and the solenoids 2001, 2002 and 2003. Each amplifier willsupply three currents having the same frequency, but dephased withrespect to each other by onethird of a phase.

The various parts described may be combined. For example, it is possibleto replace drum 20 which drives the shuttle with a spigot, by a drumsimilar to drum 22 in which only the magnetic attraction actuates theshuttle.

4. The apparatus of claim 2 wherein the means to project said grippershuttles comprises a drive wheel adjacent one semicircular channelhaving a second electromagnetic means to hold a'shuttle against thewheel during a portion of the shuttles travel through said channel,means to activate the second electromagnetic means, and a pusher elementattached to said wheel adjacent said second electromagnetic means.

5. The apparatus of claim 3 wherein the drive wheel comprises two discshaving said magnetic member therebetween.

6. The apparatus of claim 5 wherein the wheel further comprises a fixedarm extending between the two discs and supporting a hub having anannular coil therearound, said coil being spaced between the hub and'thediscs and said coil serving to create the magnetic flux through saiddiscs.

7. The apparatus of claim 5 whereinthe wheel further comprises an armextending between the discs and supporting a second smaller, freelyrotatable wheel, said second wheel being made of nonmagnetic materialand extending beyond the periphery of said discs.

8. The apparatus of claim 2 wherein the first electromagnetic meanscomprises first coils and last coils and wherein the control meanscomprises means to excite the first coils for a longer time than thelast coils.

9. The apparatus of claim 2 wherein thecontrol means comprises switchmeans adjacent the return channel to select one of a plurality ofdistributors for exciting the first electromagnetic means.

10. The combination of a curved shuttle channel, a drive wheel disposedadjacent said channel on the inner side thereof, said wheel having acentral hub and two spaced discs forming a hollow chamber therein, anannular magnetic member disposed in spaced relationship around said huband between said discs, a substantially flat arm extending outwardly ofsaid discs, a fixed support secured to said arm, a lug extendingoutwardly from said arm with a pin thereon, said lug and pin locatedwithin said chamber, a small wheel of electrically conductive materialmounted for free rotation on said pin, said wheel having a portionextending between said discs and beyond the peripheral edges of saiddiscs, said channel having an entrance and an exit, said wheel beingpositioned adjacent said exit.

11. The combination of a curved shuttle channel in which a drive wheelmember is disposed adjacent to said channel and wherein said drive wheelcomprises two spaced discs having an annular magnetic membertherebetween, said curved shuttle channel having an entrance and anexit, said exit being adjacent to a straight channel portion, saidstraight channel portion being composed of a guide wound with electricalwire which is connected with a power source for creating magnetic fieldto influence the shuttle therein, said straight channel portion beingconnected with a second curved shuttle channel in which a second drivewheel member is disposed, said second drive wheel member comprising asingle disc having on its periphery a pusher member and a magneticmember disposed adjacent the pusher member, said second curved shuttlechannel having an entrance adjacent the straight portion channel and anexit adjacent to a shed.

12. In a method of weaving in which a gripper shuttle is picked in theshed at a determined constant speed, said shuttle circulating withoutany stop in a closed circuit, said circuit including passage through ashed having an entrance and an exit, the improvement which comprisescausing said shuttle to pick up a weft yarn at the shed entrance with aconstant speed, causing said shuttle to release the yarn adjacent theshed exit, and continuously repeating the steps of picking up andreleasing the yarn while controlling the shuttle motion by a successiveand programed energization of a plurality of electromagnetic means inspaced relation within the return channel so that the shuttle alwaysreaches the shed entrance at the same point of time in each weavingcycle.

13. In a weaving loom comprising a beating means for the beating of theinserted weft in the fabric and frames to form a shed having an entranceand an exit, a return channel connecting this exit and this entranceforming with the shed a closed circuit, gripper shuttle means and meansto move said gripper shuttle means without any stop in the closedcircuit,

the beating means and the frames forming the shed being actuated inrhythm with the main shaft of the loom. the improvement comprising firstelectromagnetic means adjacent said return channel acting on the shuttlein conjunction with a successive and programed energization of aplurality of electromagnetic means in spaced relation within the returnchannel to vary the speed of this shuttle within the return channel sothat the shuttle arrives at the shed entrance at the same time inrelation with the motion of the main shaft.

14. A shuttle carrier means of a weaving loom with a gripper shuttlewith the weft thread from a fixed package located outside the shed andin which the shuttle circulates in a closed continuous path of travel,one part of same being formed by the shed and electromagnetic meansdisposed alongside another portion of said path of travel which areenergized in a successive and programed manner for controlling themovement of the shuttle passing therealong.

15. A shuttle carrier means of claim 14 comprising a closed continuouspath of travel including at least two straight portion channels and twocurved portion channels adjacent to the opposite ends of said straightportions, one of said straight portions forming the shed andelectromagnetic means disposed alongside the other straight portionchannel which are energized in a successive and programed manner forcontrolling the movement of the shuttle during its way.

